648881 has 4 divisors (see below), whose sum is σ = 653172. Its totient is φ = 644592.

The previous prime is 648871. The next prime is 648887. The reversal of 648881 is 188846.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 336400 + 312481 = 580^2 + 559^2 .

It is a cyclic number.

It is not a de Polignac number, because 648881 - 2¹⁴ = 632497 is a prime.

It is a super-2 number, since 2×648881² = 842093104322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (648887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1910 + ... + 2223.

It is an arithmetic number, because the mean of its divisors is an integer number (163293).

2⁶⁴⁸⁸⁸¹ is an apocalyptic number.

It is an amenable number.

648881 is a deficient number, since it is larger than the sum of its proper divisors (4291).

648881 is a wasteful number, since it uses less digits than its factorization.

648881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4290.

The product of its digits is 12288, while the sum is 35.

The square root of 648881 is about 805.5315015566. The cubic root of 648881 is about 86.5741731837.

Subtracting from 648881 its sum of digits (35), we obtain a palindrome (648846).

The spelling of 648881 in words is "six hundred forty-eight thousand, eight hundred eighty-one".